Skip to main content
Log in

A General Integral Method for one dimensional ablation

Ein allgemeines Integrationsverfahren für eine eindimensionale Ablation

  • Published:
Wärme - und Stoffübertragung Aims and scope Submit manuscript

Abstract

Ablation of a semi infinite medium subject to a time varying heat flux at its surface is considered. It is shown that a general integral method can be formulated to describe the post ablation solution. This method does not involve any specific approximating profile as is the case with the standard integral methods. This method, which will be referred to as the General Integral Method, yields very good solutions for problems with power law type variation in surface heat flux and also for a case where the boundary condition, involving radiation to a background, is non linear.

Zusammenfassung

Hier wird die Ablation eines halbunendlichen Mediums betrachtet, das sich einem zeitlich ändernden Wärmestrom an der Oberfläche unterwirft. Ein allgemeines Integrationsverfahren kann für die Beschreibung des Ergebnisses nach der Ablation formuliert werden. Dieses Verfahren enthält keine speziellen Näherungsprofile, wie sie bei Standardintegrationsverfahren der Fall sind. Das allgemeine Integrationsverfahren liefert sehr gute Ergebnisse für Probleme, in denen der Wandwärmestrom als Potenzfunktion beschrieben wird. Ebenso gilt dies auch für eine nicht lineare Randbedingung, wie der Strahlungsaustausch mit der Umgebung.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Institutional subscriptions

Similar content being viewed by others

Abbreviations

C :

specific heat of medium, J/kg K

H :

heat flux, W/m2

k :

thermal conductivity of medium, W/m K

L :

heat of sublimation of the ablating solid, J/kg

n :

exponent in the surface heat flux variation with time

P :

non dimensional penetration depth, after Goodman [2], defined in the text

S :

non dimensional ablation layer thickness, after Goodman [2], defined in the text

t :

time, s

t r :

reference time, {k T p (1+n/2)1/2/H so \(\sqrt \alpha\)}(2/n+1), s

T :

temperature, K

TMF :

time multiplication factor, defined in the text

x :

distance measured normal to the surface, m

X :

thickness of material removed by ablation, m

y :

non dimensional distance measured normal to the surface, (x−X)/δ

α :

thermal diffusivity of medium, m2/s

δ :

energy layer thickness, m

δ′ :

penetration depth, m

Δ :

non dimensional energy layer thickness, δ/δ p

ζ s :

non dimensional surface heat flux,H s(t)/H s(t p)

λ :

non dimensional ablation layer thickness,X p

λ′ :

normalised non dimensional ablation layer thickness, after Zien [3], λ/λ (τ→∞)

ν :

reciprocal Stefan number,L/CT p

ϱ :

density of the medium, kg/m3

σ :

Stefan-Boltzmann constant, 5.668×10−8 W/m2 K4

τ :

non dimensional time after ablation begins, (t−t p)/(t p TMF)

τ′ :

non dimensional time after Zien [3],t/t r

φ :

non dimensional surface temperature in the radiation problem, defined in the text

Θ :

non dimensional time after Goodman [2], defined in the text

e :

equilibrium condition, radiating case

p :

phase change

r :

reference value

s :

surface value

so :

amplitude of a quantity that is specified at the surface

∞:

ambient or background value in the radiating case

References

  1. Landau, H. G.: Heat conduction in a melting solid. Quart. Appl. Math. 8 (1950) 81–94

    Google Scholar 

  2. Goodman, T. R.: Heat balance integral and its application to problems involving phase change. ASME J. Heat Transfer 80 (1958) 335–342

    Google Scholar 

  3. Zien, T. F.: Integral solutions of ablation problems with time dependent heat flux. AIAA J. 16 (1978) 1287–1295

    Google Scholar 

  4. Biot, M. A.; Aggarwal, H. C.: Variational analysis of ablation for variable properties. ASME J. Heat Transfer 86C (1964) 437–442

    Google Scholar 

  5. Vallerani, E.: Integral technique solution to a class of simple ablation problems. Meccanica 9 (1974) 94–101

    Google Scholar 

  6. Altman, M.: Some aspects of the melting solution for a semi-infinite slab. Chem. Eng. Prog. Symp. Ser. 57 (1961) 16–23

    Google Scholar 

  7. Venkateshan, S. P.; Kothari, N. S.: Approximate solution of one dimensional heat diffusion problems via hybrid profiles. Int. J. Heat & Fluid Flow 8 (1987) 243–247

    Google Scholar 

  8. Carslaw, H. S.; Jaeger, J. C.: Conduction of heat in solids (2nd ed.) London: Oxford University Press 1959

    Google Scholar 

  9. Venkateshan, S. P.; Solaiappan, O.: Approximate solution of non-linear transient heat conduction in one dimension. Wärme-Stoffübertrag. 23 (1988) 229–233

    Google Scholar 

Download references

Author information

Authors and Affiliations

Authors

Rights and permissions

Reprints and permissions

About this article

Cite this article

Venkateshan, S.P., Solaiappan, O. A General Integral Method for one dimensional ablation. Wärme- und Stoffübertragung 25, 141–144 (1990). https://doi.org/10.1007/BF01590144

Download citation

  • Received:

  • Issue Date:

  • DOI: https://doi.org/10.1007/BF01590144

Keywords

Navigation